Circle divider



June 2, 1931. F. F, HEvrTzlG 1,808,110

CIRCLE DIVIDER Filed June 3, 1929 2 SheetsZ-h-eet l A ttorney CIRCLEDIVIDER Filed June 3. 1929 2 Sheets-Sheet 2 gig/5. 2.

By l.

A orney Patented June 2, 1931 UNITED STATES PATENT OFFICE FREDERICK F.HEITZIG, lO15' FIELDON, ILLINOIS v.

CIRCLE DIVIDER Application filed .Tune 3, 1929. Serial No. 368,046. l

This invention relates to geometrical instruments and has as its primaryobject the provision lof a simple and accurate instrument tor use individing circles of different 5 diameters into any desired number ofequal parts. Y n

Another veryv important object of this invention is to provide a`devic-e of the above set forth character which is very simple in l@construction, economical and simple to handle with eiliciency. vAnothervery important object oit the invention is to provide a device of thischaracter for use in all kinds of shop and 4drafting work and which willbe found to be of great aid in dividing circles into any given numberofequal parts.

"lVith'the above and numerous other objects Y in View, the inventionconsists in the. conm struction and combination of parts of which avpreferred embodiment is shown in the drawings, wherein:

Figure 1 is a top plan View of the device N, constructed ink accordancewith my invention and 'showing the same as appliedv to a disc or circleto be divided. Y

Figure 2 is 'an edgeV elevation thereof.

' Figure 3 is a front elevation showing the manner in'which thegraduated strap is disposed' about and aiiixed in position tothesemi-circular frame. v

Figure 4 lis a section taken theline 4 4 of Figure 1.

Figure 5 is a perspective Yviewof one-of the marker members. v

Figure isa vertical transverse section taken through the backing member.

'i With reference more in detail to the Ydraw-fv ings, it will be seenthat my improved circle divider comprises'a substantially semi-circularframe member designated generally by th-e reference character 5, saidmember com-` prising a substantially flat bar 6, formed' of metal or anyother suitable material,` said bar 6 at its opposite end mergingupwardly and having formed' integral therewith the adj acent end of thesemi-circular backing member I 7. The inner longitudinal edge of thefbar6 constitutes a diameter and intermediate its ends the bar 6 is cutawayV as at 8, soas to substantially on provide the center point 9. T hesemi-circular backing member 7 is at its ends JformedV integrally withth-e ends of the bars 6l and said member 7 may be also formed of vmetalor material similar to the material from which the bar 6 is made. It isto be noted that `the member 7 is in a vertical plane orin aplane atright angles to th-ebar 6. -At its bottom edge, the member 7 is providedwith a relatively narrowV rimv 8 providing a ledge or shoulder'extending for the full length oi: the said member 7. Afvery thinflexible bar or strap 10, said strap or bar preferably of springmetalisanchor'ed at one end to one extremity ofthe member 7 as at 11. YOn one face thereof, the strap 10 is provided with a suitablegraduation12. The strap 10 is consequently .used in the nature of aprotractor. A plurality of pointers or marli- Y ers 13 are adaptedfordetachable association with theV strap or protractor 10, andas shownin Figure 5, each of the markers comprise a shank portion 14 beingbevelled at one end as at 15 and the opposite end of the shank 14.merging into a hook 16, for engagement with the upperedge of the strapor protractor 10. Atits free end, the strap 10 is provided with a. rightangularly disposed plate 17, and in this connection it is to bementioned that the strap 10 is adapted to be disposedv about 'thesemi-circular 'backing' member 7 the lower vedge of said strap 10 beingadapted to rest on the bottom rim 8 as shown to advan-y tage in Figure 3and said strapv is? clamped in position about the backing 'pmember 7,through the medium of a hook 18, which en# gages the opposite extremityof the backing 1 Y' member 7 ,said hook 1S being provided with a shankportion 19, which extends downwardly along'the plate 17 Avfor securing'the same against the backing member? as shownto advantage in Figure 41:.It is'to be understood7` of course, that the lower edge of the strap l()and right angularly disposed plate v17 is i normally spaced from thework, and thatv the bevelled extremities 15 of the marker 13 extenddownwardly beyond the lower edge -ofthestrap w10 to contact with thework. The

member 10 being of flexible spring like ma- 3. Thus itV will be seenthat w viding the are ADiist the medium of terial, it will be seen thatwhen the same is disposed about the backing member 7, the rightangulaily disposed plate 17 will engage with the end of the member 7,and thus'prevent the strap 10 from swinging back out of position uponthe said backing member 7. An elongated rigid rod 2O is provided at oneend with an eye 20 through whicha pin 2l` extending from the top vedgeof the member 7 protrudes for holding said'r'od in"V engagement with themember 7.

At its opposite end, the rod 20 is also pro'- vided with an eye 20, topermit thesecuring of said end to the end of the'strap l() as at 2l.

placeand retain the strap or protractor 10 so that it is perpendicularto the diameter of tliecircle along the inner edge of the bar' 6. TheVprotractor strap 10, being of a flexible s'pringy material would,unless` clamped, in position about the member 7, naturally stand. andnearly per-- perpendicular to theework pendicular to the diameter, lItis also to be noted that' thestrap 1() is of a`width lessthan the Widthof the semi-circular backing member 7 as is clearly illustrated in igureen the strap lQ'is clamped about the backing member 7, the lower edge ofthe strap 10 will rest upon the rim 8 of the member 7, asclearlyillustrated.

The manner in which the deviceis to be used will be best illustratedinlthe following inanner. y ing problem isproposed. j Y

iven any arc of a circle,A, D, thelcircle being designated generally bythe reference character P. The circlehaving its center asV at O. Itisnow required to divide the arc AD three parts. ln di-` draw theradii'AO into, by 'way of example,

and DO. The instrument is then placed so that thec'enter point 9 of themember 6 of the' instrument Vcoincides with the center vO of the circleP. The protractor or strap' 10 is then placed about'the memberV7fandclamped' in place through the medium ofthe hooklS asl Two of thepointeror markers 13 are ythen arranged on the member l0, so thattheytouch the ra- Y dii as at AV-l and D-l.

liereinbefore more fully described.

should then be drawn around the edge of the member 7. `The protractor 10isf then unclamped and moved out to the position shown in Figure 1,'thatis to a straight line and at a tangent to theineinber 7. Therigidinember 17 is then utilized to hold the protractor/ or strap 10 inthis position.

.The position ofthe two outside pointers or markers 13 is thendesignated as at A-2 and 137-2, thus it will be seen that A-k2, B-2 is astraight line equal in length to the arcAD.

By geometric construction or ratherthrough` the graduations onl themein- Thus it will be seen'that the rod 20v when used in this mannerenables one to` As an illustration of its' use, thv'erf'ollow# ment withthe graduations thereon.V A. Y

a frame havinga The arc A-l, D-l

. s'einicircularl equal to B-lC-l equals C--l D-2 e uals- Jdie arc-A-lB-2 equals arc B-2 2 equals are C--2 D l. Therefore arc A B equals are BrC equals arc C D. Thus the arc f n D has been divided into an -equalnumber the member 7 and the position of the;

then again clamped I offparts whichfin this case wasthree equal parts.

,'Froi'n the foregoing then', it Will be seenv tliatl` have provided avery simple device for dividing 'a circle, whereby the saine may bedivided into equal parts accurately` and with a minimum expenditure'ofeffort. It is also to be understood 'that while Il have'V Ahereinshown.aiid'desciibed th'evdevice as' being of seiniecirculai" form, itis to be'uiider-i stood .thatthe same may be 'of entire circular form ifdesired.

is to be' understood that the same is suscepv'hile have hereinshownanddescribed the preterrei'l embodiment of my invention it` tible tochanges fully coinprehended bythe Y spirit of the invention asherein'described TWhat is claimed is: e l. In a circle divider, an sind barbeing formed intermedi-aterits ends to provide a center point, andaflexible strap Y and the scope ofthe appended claims. *Y

formed of spring n'iaterial having y one v endl anchored to one end ofsaid bar, andsaid strap adapted to be disposed vin aseini-circularposition, means for securing the ffree end ofsaid strap to theoppositeend-of said bar, said strap being provided with a graduated scale, anddetachable marker members 'for the strapl adapted to be Vdisposedinalign- 2. In a circle divider, center lpoint formed thereon adaptedtocoincide With 'the Vcenter of a n circle to be divided, Ian elongatedstrap" formed of flex# l 'Y 100 elongated flat bar,

ib'l'e spring material anchor-edito the frame and adapted to disliosedthereabout in-a position, means" for clamping the fi'ee'rend of thestrapin set position about the fra-ine, l

graduated scale,vand markers having hooked engagement with'the strap andadapted for alignment with the graduations on said' Strap, i v z Y. A3.In a circle divider, a framevof subst/an# tially sieinil-circularcontour, edge Vof. the: frame having a center point formedthereonadapted to coincide with the' said strap being provided with aA thestraight recano spring like strap anchored to said frame at one end ofits straight edge portion, said strap adapted to be disposed about thesemicircular portion of the frame, m'eans for detachably securing theVfree end of said strap in position about the frame, a rigid memberadapted `to be detachably secured to the frame and to the free end ofsaid strap for holding said strap at atangent to the frame, and saidstrap being provided With a graduated scale formed thereon, andseparable markers for the strap and adapted to be disposed thereon inalignment With the graduations.

4. In a circle divider, a substantially semicircular frame member, saidframe member comprising a straight edge portion, and a' semi-circularbacking portion having its ends formed integrally With the opposite endsof the straight edge portions, an elongated flexible spring-like straphaving graduations formed thereon and having one end thereof cnchored tosaid frame at one end of said straight edge portion, said strap adaptedto be disposed about th-e semi-circular backing portion of' the frame,said strap being formed at its free end With means for engaging theframe for holding the strap in said positions, a detachable clampingmeans for securing said strap in clamped position about the frame, anelongated rigid member adapted to be secured at one end to said frame,the opposite end of said rigid member adapted to engage the free end ofsaid strap for holding said strap at a tangent to said frame, andmarkers adapted for detachable association With said strap forindicating certain divisional portions of the strap. Y

5.1i device for dividing a circle comprising a relatively stationarymember of elongated conguration formed intermediate its ends to providea center point and an elongated graduated flexible member adjacentoneend thereof fixedly secured to one end of said first mentioned memberand normally extending at right angles to said first Y mentioned member,and markers` movable on said flexible member and against Which markersthe gra duations on said flexible member may be read.

6. In a circle divider, an elongated relatively rigid member formedintermediate its ends to provide a center point, an elongated flexiblemember at one end thereof secured to one end of saidfirst mentionedmember and normally extending at right anglesf thereto, said flexiblemember adapted to be bent in the are of a circle With its free endengaging the free end of said first mentioned member, said flexiblemember having gradu- Y ations formed thereon.

7. In a circle divider, an elongated relatively rigid member formedintermediate its ends to provide a center point, an elongated flexiblemember at one end thereof` secured to one end of said rst mentionedmember

